Electrical wiring

“ Another reason is that in changing the size of a wire, the underwriters require a fuse to be inserted. This makes it necessary to install a larger panel with larger trim, etc., and the consequent expense easily offsets any gain made by installing a smaller wire.
In a building covering a large area it is often advisable to install two panels or centers to a floor, with two sets of feeders. It is advisable to keep circuit lengths down to 100 feet or less, and the judicious laying out of circuit centers will save many feet of wiring. ”

“ The wireman who is called upon to plan and install a system of wiring will find it necessary first to have a knowledge of the various kinds of wire so as to select the one best suited for the work, and to be able to make simple calculations in order to determine the proper sizes of wire for the various circuits. ”

“ Fig. 1,021.—Diagram showing method of wiring for high speed effects on single lines. This wiring diagram would be carried out the same in the case of a travelling border, whether it be straight or otherwise. In the case of a fountain, begin numbering each stream at the bottom and carry out the same scheme to the end of that stream. When several streams are parallel, all the lamps may be connected in a row the same as though they were an individual lamp. Care should be taken not to get more than twenty No. 1 lamps on a circuit. ”

“ The insulated wires being drawn into them, any short circuit or heating of the wire cannot give rise to a fire, as it can only take place in the interior of a non-inflammable tube. A third system of electric light wiring is the safety concentric system, in which concentric conductors are used. The inner one, which is well insulated, consists of a copper-stranded cable. The outer may be a galvanized iron strand, a copper tape or braid, or a brass tube, and is therefore necessarily connected with the earth. ”

“ How quickly a spoon inserted into a hot cup of tea becomes uncomfortably hot, though the hand can be held very close to the liquid without feeling more than a gentle warmth. And we all have noticed that the very least air-gap in an electric circuit effectively breaks a current capable of traversing miles of wire. If the current is so intense that it insists on passing the gap, it leaps across with a report, making a spark that is at once intensely bright and hot. Metal wires are to electricity what speaking tubes are to sound; they are as it were electrical tubes through the air and ether. ”

“ It is very easy to detect the electric lines which radiate from every part of such a wire when a spark jumps between the terminals S of the coil. All that is necessary to do is to pass the wire through a sensitive film and to develop the film. The accompanying photograph (Fig. 3) was taken at the top of such a wire, by means of a very powerful apparatus at my command. When the photograph is examined with a microscope the arborescent electric lines radiating from the wire, like the rays of light Fig. 2a represents a more complete electrical arrangement of the receiver circuit. ”

“ It has already been explained that wires offer resistance to an electrical current, and that some of the energy is lost in passing through a wire because of this resistance. Small wires possess more resistance than large ones, and if small wires are to be used, in order to save on the cost of the transmission line, the loss of energy will be greater, necessitating some method of partially reducing or overcoming this fault. ”

“ The electric light company will supply a sufficiently large wire from transformer to switch; the firm does the remainder of the wiring.
FEEDERS. From this large double-pole switch (which is the main cut-off) radiate “feeder” wires to the various parts of the building, to supply the lamp circuits. These feeders have to be carefully gauged according to the number of lamps, or rather, amperes, they are required to carry, in order to avoid resistance in the wire; or in other words, must not crowd the carrying capacity of the wire, or the resistance will make the wire hot and might cause fire. ”

“ The energy of the currents and the quality of the wire also affect the speed. Until lately it was supposed that the wire acts only as a conductor of electricity, and that a long wire must produce a weaker effect than a short one, on account of the consequent attenuation of the electrical influence; but it is now known that, the cable being a reservoir as well as a conductor, its electrical supply is increased in proportion to its length. ”

“ Whenever possible, the wiring of a house, etc., for bell work, should be done as soon as the walls are up and the roof is on. The shortest and straightest convenient route from bell to battery, etc., should always be chosen where practicable to facilitate drawing the wire through and to avoid the loss of current which the resistance of long lengths of wire inevitably entails. The wires should be run in light zinc tubes nailed to the wall. ”

“ Wires were then run from the lamp socket through the cork and wood disks and the whole painted with melted paraffin to close all apertures and keep out moisture. Good rubber-covered electric-light wire will do nicely for the wiring outside the house, although, if it can be obtained, a piece of lead-covered paired wire is preferable. These wires must be only long enough to reach inside the house, where they may be joined to the ordinary sort of wire used in electric-bell work for connecting with push button and battery. ”

“ To know has become a part of the sum of life; to understand or to abandon is the rule. When the ages of tradition, of assertion without the necessity for proof, of content with all that was and was right or true because it was a standard fixed, went by, the age not necessarily of steam, or of steel, or of electricity, but the age of thought, came in. Some of the results of this thought, in one of the most prominent of its departments, I shall attempt to describe.
A wire is the usual concomitant in all electrical phenomena. It is almost the universally used conductor of the current. ”

“ If the wiring is situated where contact with electric light wires is possible, heavily insulated wires, such as are prescribed by local regulations, should be used. All permanent wire joints and splices should be snugly twisted a length of 2 inches—or, better, soldered—and wrapped with tape. All outside wires should be held by insulators. ”

“ In general wiring, use weatherproof office wire, or, better still, well-made electric light wire. For ordinary house work No. 16 B. & S. gauge is preferable; smaller wire means higher resistance and less current at burner. For braided office wire, No. 16 runs about 95 feet to the pound, No. 18 about 135 feet to the pound. The cheaper grades of wire without the patent finish or extra insulation are not worth using; sooner or later trouble will ensue, [Pg 37] and once a house is wired, it is no pleasant job to hunt trouble, especially if the wire was put on before the plaster. ”

“ Just here we may refer to the fact—for it is a fact—that the electrical energy transmitted over a line, which may be many miles in length, really does not travel by the wire connecting the two points. It travels in the ether surrounding the wire. The wire itself is, in fact, the guiding core of the disturbances in the ether which proceed outward in all directions to unlimited distances. The guiding core or conducting wire is needed to focalize or direct the delivery of the energy. ”

“ Fortunately for the future delivery of energy at great distances from its source, the means to avoid the limit just discussed are not difficult. Other experiments have shown that with a given voltage and distance between conductors the loss of energy from wire to wire decreases rapidly as their diameters increase. The electrical resistance of air, like that of any other substance, increases with the length of the circuit through it. The leakage described is a flow of electrical energy through the air from one wire to another of the same circuit. ”

“ To avoid as much as possible cutting uselessly, let every binding screw be examined and tightened up, and every length of wire, which it is possible to get at, be tested for continuity before any "slashing" at the wires, or furious onslaughts on the indicator be consummated.
In conclusion, I beg to record my thanks for the very generous assistance which I have received in the compilation of the foregoing pages from the electrical firms of Messrs. Blakey Emmot, Binswanger, Gent, Judson, Jensen, and Thorpe. ”

“ In discharging electrical jars, the electricity goes in the greatest quantity through the best conductors, and by the shortest passage. Thus if a chain and a wire be made to communicate at the same time with the outer coating of a jar, and be both presented to the knob of that jar, the greater part of the charge will pass by the wire, and very little by the chain, because the latter is a worse conductor than the former, on account of its discontinuation at every link. When the discharge is 29made by the chain only, sparks are seen at every link, which is a proof they are not in contact. ”

“ Rubber insulated copper wire covered with a double braid should preferably be used, and the duplex wire is often more convenient than the single wire, especially in running from one building to another. Wiring on the inside of buildings should be done neatly, running the wires on porcelain insulators, and as directly to the appliance as possible. ”

“ In many power plants direct current, three wire, power service is furnished by "high voltage" two wire dynamos operating in connection with balancer sets consisting of two "low voltage" machines on a common shaft. With this combination of machine, a short circuit or heavy overload on one side of the system will shift the neutral considerably, and the lamps on the opposite side may "burn out". To protect the lamps, a differential relay operating on 15 volts unbalancing, is commonly used ”

“ Underground cables, cables formed of rubber insulated wires, and interior wiring which is properly done, all may be considered to be wiring which is unexposed, that is, not exposed to foreign high potentials, discharges, sneak, or abnormal currents. All other wiring, such as bare wires, aërial cables, etc., should be considered as exposed to such hazards and a fuse should exist in each wire between its exposed portion and the central office or subscriber's instrument. ”

“ When wire is wound by hand from a spool into a coil, or around a core, it soon becomes twisted and tangled. Make a winder. This will keep the wire straight and save much time.
APPARATUS 81.
Fig. 54.
108. Electro-Magnet. Fig. 54. Drive a nail into a board so that it will project about 3⁄4 of an inch. A soft, or wrought-iron, nail is best, but a short, thick wire-nail will do. If you do not have a thick nail, use an iron screw. Wind 3 or 4 layers of insulated copper wire around it, and fasten the bare ends of the wire down with bent pins. ”

“ All wires and current carrying parts should be kept far enough apart at all points to prevent accidental contact or the jumping across of the 428 current where there is a great difference of voltage. Such wires should be also kept at a sufficient distance from screw heads, metal brackets, gas pipes, water pipes, and other conducting bodies, in order to prevent accidental grounds or short circuits. ”

“ As shown in fig. 638, a wire AX, of non-oxidizable metal, of high resistance and low temperature coefficient, passes over a pulley B mounted on the shaft C. The ends of the wire are attached to the plate E at its ends F and G, the wire being insulated from the plate at G. A spring H holds the wire in tension and takes up the slack due to the expansion caused by the heating of the wire when a current passes through it. ”

“ In other cases, if it be a three-heat stove, the three wires are directly connected with the heating element and all that has to be done in case of bad connection is to raise the heating element and unscrew the wires. In other styles when bad connection occurs you must search the surface beneath the plug, a little more complicated operation, but still the manufacturers of this feel that it is an added protection to wiring. ”

“ On the back of this mounting strip all the wiring is done and much of this wiring—that connecting adjacent terminals on the back of the relay strip—is made by means of thin copper wires without insulation, the wires being so short as to support themselves without danger of crossing with other wires. When these wires are adjacent to ground or battery wires they may be protected by sleeving, so as to prevent crosses. ”

“ The annunciator has a bell to call attention. A cable of six wires enters this annunciator (Fig. 36) . One wire goes direct to the bell and the other five reach the bell through the separate coils of the electro-magnets which control the drops. But how are [70] electrical connections made between a moving elevator car and the push buttons on various floors? The diagram in Fig. 37 shows this in elevation. B represents a battery of several dry cells located in the basement. One wire from it runs direct to the push buttons 1, 2, 3, 4, 5, located upon the five floors of the house. ”

“ If the shaft which supports the loop is rapidly revolved; a current of electricity will be set up in the wire loop by bridging over the space at the ends of the wire between the metal plates with a piece of metal or another loop of copper wire; copper always being used to conduct electricity where it can be, for the reason that it is the best practical conductor of electricity. ”